Guidance apparatus of unmanned autonomous operating vehicle

1. An apparatus for guiding an unmanned autonomous operating vehicle having an electric motor supplied with power from a battery for operating an operating machine, prime movers for driving wheels, and magnetic sensors for detecting intensity of a magnetic field of an area wire, the vehicle being controlled to run about in an operating area defined by the area wire through wheels driven by the prime movers to perform an operation using the operating machine and to return to a charging device installed on the area wire so as to charge the battery, wherein the apparatus comprises a controller configured to control the vehicle in an operating mode and in a return mode, wherein in the operating mode, the controller controls the vehicle to run about in the operating area to perform the operation using the operating machine, and in the return mode, the controller controls the vehicle to run on the area wire so as to return the vehicle to the charging device, and at a position near the charging device, the area wire is laid with an offset to right or left when viewed in a plane such that, as the controller controls the vehicle in the return mode to run on the area wire and the offset of the area wire to the charging device for connection with the charging device, the vehicle is turned from a straight-running position to a direction of the offset and then is returned to the straight-running position, thereby guiding the vehicle to the charging device.

2. The apparatus according to claim 1 , wherein the magnetic sensors comprise a right magnetic sensor and a left magnetic sensor installed on both sides of a vehicle body, and the area wire is made offset from a line connecting a mid point between the right and left magnetic sensors with a longitudinal center line of the vehicle body by a predetermined distance.

3. The apparatus according to claim 2 , wherein the predetermined distance is a value equal to or greater than a distance from the line connecting the mid point and the longitudinal center line to one of the magnetic sensors on a side of the offset.

4. The apparatus according to claim 1 , wherein the wheels include front wheels and rear wheels and the vehicle is a rear-wheel-drive type vehicle in which the rear wheels are driven.

5. The apparatus according to claim 1 , wherein the vehicle has a charging terminal at its front to be connectable with the charging device installed on the area wire.

6. The apparatus according to claim 1 , wherein the operating machine comprises a lawn mower for mowing lawn on a ground.

7. The apparatus according to claim 1 , wherein the charging device is disposed with a coil radiating a magnetic field that forms a charging device detecting area around the charging device.

8. The apparatus according to claim 1 , wherein the controller is configured to control the vehicle, in the return mode, to run on the area wire while slightly swinging a front portion of the vehicle so that the front portion of the vehicle is directed and positioned alternately inside and outside of the operating area.

9. The apparatus according to claim 1 , wherein the offset includes a first offset portion and a second offset portion that are continuous with each other, and the second offset portion is offset by an amount smaller than that of the first offset portion.